Fluorous mixture synthesis of (-)-dictyostatin and three stereoisomers.

A mixture of four stereoisomers whose configurations are encoded by fluorous silyl protecting groups has been prepared and converted over 22 steps to a mixture of protected dictyostatins. Demixing by fluorous HPLC followed by removal of the fluorous protecting groups (detagging) provides dictyostatin and three C6,C7 stereoisomers. Biological evaluation showed that the monoepimers of the natural product retained highly potent activity.\ud \u